The Effect of Different Methods of Modification on the Surface Properties and on the Finale Strength of Bonded Joints of Selected Types Thermoplastics

2017 ◽  
Vol 1142 ◽  
pp. 188-193
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Ales Mizera ◽  
Martin Reznicek ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Properties ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Wide Range ◽  
Bonded Joint ◽  
Almost All ◽  
Contact Angle Of Wetting

In this study there was compared the effect of different methods of modification (modification by plasma treatment and ionizing beta radiation) on the surface properties (contact angle of wetting and surface free energy) and on the final strength of bonded joints of selected types thermoplastics (low density polyethylene and polycarbonate). At the present time bonding has spread into almost all sectors of practice and it would be very difficult to find an industry in which there is no need to use this technology of joining a wide range of materials. Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface energy than the solid in order to be able to wet the solid substance.

Effect of Beta Irradiation on the Strength of Bonded Joints of HDPE

2013 ◽  
Vol 586 ◽  
pp. 79-82 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Martin Ovsik ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Contact Angle ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
New Combination ◽  
Bonded Joints ◽  
Solid Substance ◽  
Wide Range ◽  
Bonded Joint ◽  
Almost All ◽  
Contact Angle Of Wetting

At the present time bonding has spread into almost all sectors of practice and it would be very difficult to find an industry in which there is no need to use this technology of joining a wide range of materials. In comparison with conventional joining methods (riveting, welding and screwing) provides bonding new combination of options and allows obtaining special shapes and properties which cannot be created by conventional methods of coupling. For the formation of quality bonded joint it is important that the adhesive bonding surface is well wetting. Wettability is characterized by the contact angle of wetting. The liquid must have a lower surface tension than the solid in order to be able to wetting the solid substance. This article describes the effect of beta irradiation on the contact angle of wetting, on the surface energy and on the final strength of bonded joints of HDPE.

scholarly journals Effect of Ionizing Beta Radiation on the Strength of Bonded Joints of Polycarbonate

2014 ◽  
Vol 1025-1026 ◽  
pp. 251-255 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polycarbonate. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 50 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

Strength of Bonded Joints of Polypropylene after Radiation Cross-Linking

2015 ◽  
Vol 1120-1121 ◽  
pp. 1167-1170
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Bonded Joint ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polypropylene (PP). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polypropylene. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66 and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PP were achieved. The strength of bonded joints after irradiation was increased up to 450 % compared to untreated material. A similar trend was observed even for surface energy.

Strength of Bonded Joints of Linear Low – Density Polyethylene after Radiation Cross – Linking

2014 ◽  
Vol 1025-1026 ◽  
pp. 615-620 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Beta Radiation ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Bonded Joints ◽  
Linear Low Density Polyethylene ◽  
Adhesion Properties ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of linear low – density polyethylene (LLDPE). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of linear low – density polyethylene. Bonded surfaces with ionizing beta radiation doses of 0, 66, 132 and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 132 kGy by which the highest surface energy and the highest strength of bonded joints of LLDPE were achieved. The strength of bonded joints after irradiation was increased up to 60 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

Influence of Ionizing Beta Radiation on the Surface Energy and Strength of Bonded Joints (at an Elevated Temperature) of Thermoplastic Material

2015 ◽  
Vol 752-753 ◽  
pp. 378-381
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Bonded Joint

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Bonded joints at elevated temperature (60 °C) were tested. Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface energy than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for improvement of adhesive properties and increased the strength of bonded joints of PC at elevated temperature (60 °C). Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, 99, 132, 165 and 198 kGy were irradiated. The best results were achieved by irradiation at doses of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 10 % and surface energy up to 30 % compared to untreated material.

scholarly journals Defects and uncertainties of adhesively bonded composite joints

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Sadik Omairey ◽  
Nithin Jayasree ◽  
Mihalis Kazilas
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Production Efficiency ◽  
Adhesive Bonding ◽  
Detection Methods ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Wide Range ◽  
Bonded Composite

AbstractThe increasing use of fibre reinforced polymer composite materials in a wide range of applications increases the use of similar and dissimilar joints. Traditional joining methods such as welding, mechanical fastening and riveting are challenging in composites due to their material properties, heterogeneous nature, and layup configuration. Adhesive bonding allows flexibility in materials selection and offers improved production efficiency from product design and manufacture to final assembly, enabling cost reduction. However, the performance of adhesively bonded composite structures cannot be fully verified by inspection and testing due to the unforeseen nature of defects and manufacturing uncertainties presented in this joining method. These uncertainties can manifest as kissing bonds, porosity and voids in the adhesive. As a result, the use of adhesively bonded joints is often constrained by conservative certification requirements, limiting the potential of composite materials in weight reduction, cost-saving, and performance. There is a need to identify these uncertainties and understand their effect when designing these adhesively bonded joints. This article aims to report and categorise these uncertainties, offering the reader a reliable and inclusive source to conduct further research, such as the development of probabilistic reliability-based design optimisation, sensitivity analysis, defect detection methods and process development.

scholarly journals Surface toughening – An industrial approach to increase the robustness of pure adhesive joints with film adhesives

2020 ◽  
Vol 234 (13) ◽  
pp. 1980-1987
Author(s):  
MJ Schollerer ◽  
J Kosmann ◽  
D Holzhüter ◽  
C Bello-Larroche ◽  
C Hühne
Keyword(s):  
Large Scale ◽  
Adhesive Bonding ◽  
Bolted Joints ◽  
Small Scale ◽  
Bonded Joints ◽  
Fiber Reinforced ◽  
Load Path ◽  
Stress Concentrations ◽  
Manufacturing Defects ◽  
Wide Range

Bonding is known for its wide range of advantages over bolted joints when joining different materials together. However, the advantages e.g. of homogeneous load distribution can quickly be lost in case of overload. For this reason, the load occurring in the adhesive is reduced by constructive measures far below the yield stress of the adhesive, which leads to a conservative joint design. And to be on the safe side, a few “chicken rivets” are then placed again. This problem is particularly well known in aviation. Highly loaded components are structurally bonded by a combination of rivets and adhesive in order to underline the advantages of structural adhesive bonding with the safety of the well-known bolted joints. Known as fail-safe design, this concept is damage tolerant and more robust against manufacturing defects through a secured double load path.  Especially when joining fiber-reinforced composites, bolts weaken the adherends of the joint and only contribute to load transfer when the brittle adhesive fails. With the help of Surface Toughening, a boltless technique for reducing stress concentrations and arresting cracks in adhesive bonded joints is available. This work describes the industrial application of this technique. Starting with coupon tests and a small scale demonstrator to ensure the compatibility with industrial manufacturing processes, such as infusion and prepreg manufacturing, a large scale demonstrator of a 2 m carbon fiber reinforced plastic (CFRP) - HTP leading edge with hybrid laminar flow control is manufactured by the industrial partner AERnnova. Verifying a simple and cost-effective application of the technology, Surface Toughening enables robust bonded joints with a minimum impact on today's process of adhesive bonding.

The Wetting of Insect Cuticles by Water

1955 ◽  
Vol 32 (3) ◽  
pp. 591-617 ◽  
Author(s):  
M. W. HOLDGATE
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Properties ◽  
Surface Composition ◽  
Contact Angles ◽  
Aquatic Species ◽  
Water Contact ◽  
Calliphora Erythrocephala ◽  
Wetting Properties ◽  
Wide Range

1. The water contact angles of insects show a wide range of variation, which is broadly correlated with surface roughness and with habitat. 2. The contact angles of species inhabiting stored products or carrion are greatly modified by contamination. This produces large variations between apparently similar individuals. 3. In terrestrial insects surface roughness increases the contact angles to very large apparent values. Detailed analyses of its effect have been made in the pupa of Tenebrio molitor and the adult Calliphora erythrocephala. In some aquatic insects surface roughness leads to a reduction in the contact angles; this has been studied in the nymph of Anax imperator. 4. Prolonged immersion in water causes a lowering of the contact angles of all the insects examined, and the low angles of many aquatic species may therefore be the direct effect of their environment. In some aquatic species there is evidence of the active maintenance of a large contact angle during life. 5. Changes in contact angle accompany processes of cuticle secretion and will occur at any moult if changes in roughness or habitat take place. 6. The observed variations of surface properties can be explained without assuming any variation in the chemical composition of the cuticle surface. Wetting properties are of little value as indicators of cuticle surface composition. 7. The biological aspects of insect surface properties are briefly discussed.

scholarly journals INFLUENCE OF AGEING ON RIVET‐BONDED JOINT PROPERTIES

Aviation ◽  
2005 ◽  
Vol 9 (2) ◽  
pp. 24-28
Author(s):  
Petr Kachlík ◽  
Josef Klement
Keyword(s):  
Thermal Cycling ◽  
Adhesive Bonding ◽  
Hydraulic Fluid ◽  
Bonded Joints ◽  
Polyurethane Adhesive ◽  
Hybrid Joining ◽  
Joining Technology ◽  
Joint Properties ◽  
Bonded Joint ◽  
Aircraft Engineering

Riveting and adhesive bonding are common joining technology in aircraft engineering. A hybrid joining such as rivet‐bonding brings together the benefits of both basic techniques whilst minimising some of their shortcomings. These technologies have been present mastered sufficiently, and their characteristics are well known. Due to different influences in aircraft service (weather, location of aircraft operation, air composition, contact with fuel or hydraulic fluid), a degradation of the characteristics of joints is well noticed. This research was focused on the ageing of rivet‐bonded joints with a polyurethane adhesive and blind rivets and the influence of ageing on the properties of joints. Ageing according EN 2243–5 was carried out in hot/wet conditions, salt mist, hydraulic fluid, and fuel. Thermal cycling was used as a resource of ageing.

scholarly journals Effect of Beta Radiation on the Quality of the Bonded Joint for Difficult to Bond Polyolefins

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1863 ◽  
Author(s):  
David Manas ◽  
Martin Bednarik ◽  
Ales Mizera ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
...  
Keyword(s):  
Surface Layer ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Significant Extent ◽  
Surface Layers ◽  
Adhesive Bonds ◽  
Polymer Properties ◽  
Bonded Joint ◽  
Significant Attention

Bonding is increasingly being used, and it is an ever-evolving method for creating unbreakable bonds. The strength of adhesive bonds determines, to a significant extent, the possible applications of this technology and is influenced by many factors. In addition to the type of adhesive used, the characteristics of the surface layers play a significant role; therefore, significant attention is paid to their adjustment and modification. Radiation crosslinking is one of the most important methods for modifying polymer properties. Currently, the most frequently used type of radiation for polymer crosslinking is beta minus (β−) radiation, which affects not only mechanical but also surface properties, chemical and temperature resistance, and surface layer characteristics of polymers. This study investigated the effect of β− radiation on the surface layer properties of low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP) and the effects of surface-layer modification on the ultimate tensile strength of bonded joints. Based on the results, we concluded that β− radiation significantly changes the properties of the tested surface layers, increases the surface energy, and improves the adhesiveness of bonds. Consequently, the final strength of the LDPE, HDPE, and PP bonds increases significantly.

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